For around a year I've been harvesting my yeast from starters. I found the method through this post on Brulosophy . So far, it's been incredibly valuable in ways I didn't foresee. The method itself is simple, but what I found most interesting was the way that I approached the age old question of "what to brew next."
At first I was brewing with the same two yeasts I harvested first. But then when I decided to take a turn and try something new, it was easy to justify picking up a new yeast. I could bank it and use it in the future too. And when a seasonal yeast comes out, or an obscure strain is released from the white labs vault, I pick it up without hesitation. I'm not a thrifty person, but for some reason this technique has given me freedom in knowing that I spin up an old trusty or pickup something new and play with it over and over.